Cannot specify securityContext container attribute

[franck102]

This is an improvement request

Describe the bug The timescaledb-single chart won't let you configure a securityContext container attribute. This is required in Kubernetes clusters that use pod security policies (else the container start as root and postgres refuses to start):

containers:
        - name: timescaledb
          securityContext:
            allowPrivilegeEscalation: false
            runAsGroup: 1000
            runAsNonRoot: true
            runAsUser: 1000

We have to create a local copy of the chart to work around this issue.

[feikesteenbergen]

The Single Helm Chart defaults to the default securityContext, which:

Defaults to user specified in image metadata if unspecified.

https://v1-18.docs.kubernetes.io/docs/reference/generated/kubernetes-api/v1.18/#securitycontext-v1-core

Which is postgres for this image.

docker inspect timescaledev/timescaledb-ha:pg12.5-ts2.0.0-p0 | jq '.[0].Config.User' -r
postgres

However, it may be good to explicitly configure this setup. See #252